In 1866, the U.S. Congress passed the Civil Rights Bill of 1866, which granted African Americans the rights and privileges of U.S. citizenship and formed the basis for the 14th Amendment.

In 1939, on Easter Sunday, African-American contralto Marian Anderson gave a free open-air concert before more than 75,000 people from the steps of the Lincoln Memorial in Washington after the Daughters of the American Revolution denied her use of Constitution Hall because of her race.

In 1940, Germany invaded Norway and Denmark.

In 1947, a tornado roared through at least 12 towns in Texas, Oklahoma and Kansas, killing 169 people. The twister traveled 221 miles across the three states.

In 1959, the National Aeronautics and Space Administration introduced America's first astronauts to the public. The seven men -- military test pilots M. Scott Carpenter, L. Gordon Cooper, John H.Glenn, Virgil I. "Gus" Grissom, Walter M. "Wally" Schirra, Alan B. Shepard and Donald K. "Deke" Slayton -- were selected from a group of 32 candidates to take part in Project Mercury.

In 1963, by an act of the U.S. Congress, British statesman Winston Churchill became an honorary U.S. citizen.

In 1965, the Astrodome opened in Houston for the first indoor Major League Baseball game.

In 1976, the United States and Soviet Union agreed on the size of nuclear tests for peaceful use.